Files
revng-revng/lib/DataLayoutAnalysis/DLAPass.cpp
T
Pietro Fezzardi 7c1021ffc1 DLA: rearrange Middleend steps
Now CompactCompatibleArrays runs after ArrangeAccessesHierarchically.
Rearranging the accesses hierarchically first allows the following step,
that compacts compatible arrays, to achieve better results, and overall
recover much better looking arrays.
2023-12-05 16:59:08 +01:00

130 lines
4.7 KiB
C++

//
// Copyright (c) rev.ng Labs Srl. See LICENSE.md for details.
//
#include "revng/Model/LoadModelPass.h"
#include "revng/Pipeline/Context.h"
#include "revng/Pipeline/LLVMContainer.h"
#include "revng/Pipeline/RegisterAnalysis.h"
#include "revng/Pipes/Kinds.h"
#include "revng/Pipes/ModelGlobal.h"
#include "revng-c/DataLayoutAnalysis/DLALayouts.h"
#include "revng-c/DataLayoutAnalysis/DLAPass.h"
#include "revng-c/Pipes/Kinds.h"
#include "Backend/DLAMakeModelTypes.h"
#include "Frontend/DLATypeSystemBuilder.h"
#include "Middleend/DLAStep.h"
char DLAPass::ID = 0;
static Logger<> BuilderLog("dla-builder-log");
using Register = llvm::RegisterPass<DLAPass>;
static ::Register X("dla", "Data Layout Analysis Pass", false, false);
void DLAPass::getAnalysisUsage(llvm::AnalysisUsage &AU) const {
AU.addRequired<LoadModelWrapperPass>();
AU.addRequired<llvm::ScalarEvolutionWrapperPass>();
AU.addRequired<FunctionMetadataCachePass>();
AU.setPreservesAll();
}
bool DLAPass::runOnModule(llvm::Module &M) {
llvm::Task T(3, "DLAPass::runOnModule");
T.advance("DLA Frontend");
auto &ModelWrapper = getAnalysis<LoadModelWrapperPass>().get();
auto &Cache = getAnalysis<FunctionMetadataCachePass>().get();
// Front-end: Create the LayoutTypeSystem graph from an LLVM module
dla::LayoutTypeSystem TS;
dla::DLATypeSystemLLVMBuilder Builder{ TS, Cache };
const model::Binary &Model = *ModelWrapper.getReadOnlyModel();
Builder.buildFromLLVMModule(M, this, Model);
if (BuilderLog.isEnabled())
Builder.dumpValuesMapping("DLA-values-initial.csv");
// Middle-end Steps: manipulate nodes and edges of the DLATypeSystem graph
T.advance("DLA Middleend");
dla::StepManager SM;
size_t PtrSize = getPointerSize(Model.Architecture());
revng_check(SM.addStep<dla::RemoveInvalidPointers>(PtrSize));
revng_check(SM.addStep<dla::CollapseEqualitySCC>());
revng_check(SM.addStep<dla::CollapseInstanceAtOffset0SCC>());
revng_check(SM.addStep<dla::SimplifyInstanceAtOffset0>());
revng_check(SM.addStep<dla::PruneLayoutNodesWithoutLayout>());
revng_check(SM.addStep<dla::ComputeUpperMemberAccesses>());
revng_check(SM.addStep<dla::RemoveInvalidStrideEdges>());
revng_check(SM.addStep<dla::PruneLayoutNodesWithoutLayout>());
revng_check(SM.addStep<dla::ComputeUpperMemberAccesses>());
revng_check(SM.addStep<dla::MergePointerNodes>());
revng_check(SM.addStep<dla::DecomposeStridedEdges>());
// CollapseSingleChild and DeduplicateFields run becore
// CompactCompatibleArrays and ArrangeAccessesHierarchically, to allow them to
// produce better results
revng_check(SM.addStep<dla::CollapseSingleChild>());
revng_check(SM.addStep<dla::DeduplicateFields>());
revng_check(SM.addStep<dla::ArrangeAccessesHierarchically>());
revng_check(SM.addStep<dla::CompactCompatibleArrays>());
revng_check(SM.addStep<dla::PushDownPointers>());
// ArrangeAccessesHierarchically can move pointer edges around in some cases,
// so we want to run MergePointerNodes again afterwards.
revng_check(SM.addStep<dla::MergePointerNodes>());
// CollapseSingleChild and DeduplicateFields run again after
// CompactCompatibleArrays and ArrangeAccessesHierarchically, to allow them to
// improve the results even further.
revng_check(SM.addStep<dla::ResolveLeafUnions>());
revng_check(SM.addStep<dla::CollapseSingleChild>());
revng_check(SM.addStep<dla::DeduplicateFields>());
revng_check(SM.addStep<dla::ComputeNonInterferingComponents>());
SM.run(TS);
// Compress the equivalence classes obtained after graph manipulation
dla::VectEqClasses &EqClasses = TS.getEqClasses();
EqClasses.compress();
dla::LayoutTypePtrVect Values = Builder.getValues();
if (BuilderLog.isEnabled())
Builder.dumpValuesMapping("DLA-values-after-ME.csv");
T.advance("DLA Backend");
// Generate model types
auto &WritableModel = ModelWrapper.getWriteableModel();
auto ValueToTypeMap = dla::makeModelTypes(TS, Values, WritableModel);
bool Changed = false;
Changed |= dla::updateFuncSignatures(M, WritableModel, ValueToTypeMap, Cache);
Changed |= dla::updateSegmentsTypes(M, WritableModel, ValueToTypeMap);
revng_assert(WritableModel->verify(true));
return Changed;
}
class DLAAnalysis {
public:
static constexpr auto Name = "dla";
std::vector<std::vector<pipeline::Kind *>> AcceptedKinds = {
{ &revng::kinds::StackAccessesSegregated }
};
void run(pipeline::Context &Ctx, pipeline::LLVMContainer &Module) {
using namespace revng;
llvm::legacy::PassManager Manager;
auto Global = llvm::cantFail(Ctx.getGlobal<ModelGlobal>(ModelGlobalName));
Manager.add(new LoadModelWrapperPass(ModelWrapper(Global->get())));
Manager.add(new DLAPass());
Manager.run(Module.getModule());
}
};
pipeline::RegisterAnalysis<DLAAnalysis> DLCPipelineReg;